A cobra is a venomous snake famous for the dramatic way it raises the front part of its body and spreads out the skin of its neck into a wide, flat hood when it feels threatened. This hood makes the cobra look bigger and more intimidating, like a warning sign that says “stay back!”

Cobras live in warm regions of Africa and Asia. The king cobra, which can grow over 18 feet long, is the world's longest venomous snake. Despite their fearsome reputation, cobras usually prefer to avoid conflict. They only strike when they feel cornered or are defending themselves. In some cultures, cobras appear in mythology and art as symbols of power and protection.

The word also describes certain military helicopters. The AH-1 Cobra, used by the U.S. Marine Corps, got its name because it's fast, agile, and dangerous to enemies, just like the snake. When engineers name military equipment after animals, they're usually highlighting qualities like speed, strength, or stealth.